physics
A electric model train travels at 0.339 m/s around a circular track of radius 1.75 m. How many revolutions does it perform per second, i.e, what is the motion's frequency?March 14, 2013

physics
A electric model train travels at 0.339 m/s around a circular track of radius 1.75 m. How many revolutions does it perform per second, i.e, what is the motion's frequency?March 14, 2013

Chemistry
During an experiment, a student adds 0.339 g of calcium metal to 100.0 mL of 2.05 M HCl. The student observes a temperature increase of 11.0 °C for the solution. Assuming the solutions' final volume is 100.0 mL, the density is 1.00 g/mL, and the specific heat is 4.184 ...January 28, 2013

earth
Suppose that an object on Earth has a known mass of 80 kgs. Will the mass of that object be less than, more than, or the same as on the other planets in our solar system? Explain your answer.March 14, 2012

Physics
A bucket full of water (15kg) is swung in a vertical circle on a rope 1.5m long. What is the minimum speed it can be swung so that the water doesn't fall out at the top? Which equations should I start with first?November 3, 2010

AP Chemistry
Each increase in pressure of 100 atm decreases the melting point of water by 1.0 degrees C. Estimate the temperature at which liquid water freezes under a pressure of 400 atm. How do I approach this problem?October 27, 2010

Physics
My problem question: "A ball is thrown up onto a roof, landing 4.0 seconds later at a height of 20.0 m above where it was thrown. The ball's velocity vector upon landing on the roof top was angled 60 degrees to the horizontal flat roof top. Find the horizontal ...October 7, 2010

Writing
i'm writing a rhetorical paper on the film, Blade Runner. How do i analyze a film? what are the main points that i'm suppose to look for?February 22, 2008

chemistry
i don't think it's correct if we take the ratio of the absorbance because both are not from one concentration.February 22, 2008

chemistry
The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.500. If a trial's absorbance is measured to be 0.310 and its initial concentration of SCN was 0.0010 M, the equilibrium ...February 22, 2008

chemistry
A standard solution of FeSCN2+ is prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN. The equilibrium concentration of FeSCN2+ ([FeSCN2+]std) for this standard solution is assumed to be ?M.February 22, 2008

history
the major event preceding the founding of the nation and relate their significance to the development of AmericaAugust 30, 2007